That's my second biggest problem with what Rodney did (after-it's illegal, and nice way to treat your friend!) - he took John off-world! Anything could have happened! Where's his survival instinct? His common sense?

I guess that lack of strategic thinking is why Sheppard beats him at chess. Outside of physics, McKay is frequently quite a moron. Which I actually had no problem with initially. I liked the idea of a character who wasn't a hero but was certainly no villain. But later in the series it seemed like instead having the audience laugh at what an thoughtless jerk McKay could be, the writers expected us to laugh with McKay because he'd hurled a zinger at one of the beautiful people.
The thing is, I realize SGA is not known for its follow-through on consequences, but as illegal as it is to give someone a mind altering drug, giving it to the CO of the base before he goes on mission? I'd expect to see McKay in a military jail after that.

In the Return'verse at least, John knows this and so doesn't mention it to Cam, because Rodney's still his best friend, and he wants them to get along. But yeah, unpleasant outcomes if Cam found out.
John is a better man than I am. I really can't see myself getting over something like this.
I plan to amuse myself on my boring commute by imagining what happens when Cam finds out what McKay did to John. I feel another mini-catharsis coming on.